Manufacture of sheet glass



H. F. CLARK.

MANUFACTURE OF SHEET GLASS. APPLICATION FILED AUGn5. 1919. RENEWED DEC.26. I921.

Patented Aug. 1, 1922.

HENRY F. CLARK, 01F BELLE VERNON, PENNSYLVANIA, ASSIGNOR T0 WINDOW GLASSJERSEY.

amas.

Application filed August 5, 1919, Serial No. $15,426. Renewed. December26, 1921.

To all whom it may concern:

Be it known that I, HENRY F. CLARK, a citizen of the United States,residing at Belle Vernon, in the county of Fayette and State ofPennsylvania, have invented a new and useful Improvement in theManufacture of Sheet Glass, of Which the following is a full, clear, andexact description, reference be ng bad to the accompanying drawing,forming part of this specification, in which Figure 1 is alongitudinalvertical section of a portion of a glass drawing apparatus, partlyconventional.

Figure 2 is a plan view of the hot air distributor, and

Figure 3 is a plan view of a modified form of hot air distributor.

My invention has relation to the manufacture of sheet glass, and moreparticularly tothat method of manufacture known as sheet drawing inwhich the glass, instead of being drawn in cylinder form and subsequentlsplit and flattened into sheets, is initial y drawn in sheet form.

In such method, one of the difficultles which has been encountered andwhich has made it difiicult to produce commercial glass of the highergrades, in quantities, is the pimpled or roll-marked character of thesurface of the glass when it contacts with the roll or rolls used in thedrawing apparatus. My invention is designed to overcome this difiicultyand to enable the production of sheet glass which is largely if notwholly free from objectionable pimpling and '-which will equal inquality the glass made by cylinder drawing methods.-

Herein, I have illustrated my invention ,as applied-to that form ofsheet drawing in which the continuous sheet is first drawn from theglass bath in a vertical direction and isthen bent horizontally over abending roller and carried through an anneallng chamber or lehr; but itwill be understood that it may be equally used in connection with othermethods of sheet drawing in which the difliculty above noted isencountered. Also that various changes may be made in the form andarrangement of the apparatus employed, without departing from the spiritand scope of my invention as defined in the claims.

In the accompanying drawing, the numeral 2 designates a portion of anusual receptacle containing the glass ath from Specification of LettersPatent.

MANUFACTURE OF SHEET GLASS.

Patented Aug. 11, 192%. Serial No. 524=,fi14.

which the sheets are to be drawn and 3 a bending roller over which-thevertically rising sheet. is bent in a horizoiital direction and iscarried by suitable gripping aparatus into an annealing chamber 4.

rawing apparatus of the character here partially. and conventionallyillustrated forms in itself no part of my present inventlon, and as itis well known in the art, need not herein be more specificallyillustrated and described.

In accordance with my invention, I provide means for heating andsoftening the under surface of the glass sheet immediately after suchsurface passes out of contact with the bending roll, and at a time whenthe temperature of the sheet is below that of v plasticity. The actionof such means is substantially a fire-flashing which is sufiicient tofuse, or partially fuse, the immediate surface of the sheet to an extentwhich will obliterate the objectionable pimpling of such surface. Thisfire-flashing can be accomplished either by air preheated to. thenecessary temperature and directed against the surface of the glass orby gas or oil fumes directed against such surface. In the drawing I-have illustrated a distributor 5 for preheated air or gas. This isplaced transversely of the glass sheet at its underside and is formedeither with a continuous jet opening 6, or a Iplurality of staggered jetopenings 7 (see ig. 3) through which the heated fluid is directed intocontact with the under surface of the glass sheet 8. Shortly, back ofthe flashing jet, I may employ a coolin jet 9 to solidify the softenedsurface, when ound necessary.

My invention provides simple tive method and means capable ofbeing'applied to and used in connection with existing drawing apparatusat a relatively small cost, whereby the quality of the drawn glass canbe greatly improved. The action of the flashing jet, by softening thesurface portion only 'of the glass, removes the marks or pimples causedb the rolls and gives the surface a good pollsh. My invention may beused in connection with other known means "for minimizing the difficultyabove re and effecnot i 6 heated jet, Substantially as described.

2. The method of drawing glass sheets, consisting in drawing acontinuous sheet upwardly from a molten glass bath, bending it over abending device and moving it in a- .generally horizontal direction, andsubject ing the unde'rsurface in'its horizontally extending portion tothe action of a heated jet followed'by that of a cooling jet,substantially as described. I

3. In the drawing of glass sheets,'the improvement which consists indrawing a continuous sheet; over the surface of a roll, and immediatelythereafter subjecting the rollcontacting surface of the sheet to theaction of'a heated jet, substantially as described. 4. In the drawingof-glass sheets, the improvementv which consists in drawing a continuoussheet over the surface of a roll, and immediately thereafter subjectingthe rollcontacting surface of the sheet to the action ofa heated jetfollowed by thatof a cooling jet, substantially as described.

5. The method .of drawing glass sheets,-

.consisting in drawing a continuous sheet upwardly from a molten glassbath, bending it j over a bending deviceand moving it in agenerally-horizontal direction. fire flashing applying the under-surfaceof the sheet immediately after it passes the bending device, and then acooling jet toits under surface, substantially as described.

6. In the drawing of glass sheets, the improvement which consists indrawing a continuoussheet vertically from a glass bath, bending thesheet over a" roll onto a horizontal path, and causing theroll-contacted surface of thesheet to then pass in contact with afire-flashing jetand then in contact with a cooling jet, substantiallyas described. 7. In apparatus for drawing glass sheets from a moltenbath, a bending device, means for drawing a continuous sheet upwardly ina vertical direction and thence over a bendin-g device in a generallyhorizontal direction, and means for fire flashing the under side of thesheet after it device, substantially as described.

' 8. In apparatus for drawing glass sheets from a molten bath, a bendingdevice, means for drawing a continuous sheetupwardly in.

a vertical direction and thenceover a bending device in a ener'allyhorizontal direction, means for re flashing the under side of the sheetafter it passes the bending device, and means for cooling the fire flashsurface, substantially as described.

In testimony whereof, I have hereunto set in hand. y HENRY F. CLARK.

passes the bending

